Schweitzer Engineering Laboratories SEL-311C - Figure 3.32 Angle Difference between V

3.51
Date Code 20060320 Instruction Manual SEL-311C Relay
Distance, Out-of-Step, Overcurrent, Voltage, Synchronism Check, and Frequency Elements
Synchronism Check Elements
Figure 3.32 Angle Difference Between V
P
and V
S
Compensated by Breaker
Close Time (f
P
< f
S
and V
P
Shown as Reference in This Example)
If the slip frequency is greater than 0.005 Hz, the Angle Difference Calculator
takes the breaker close time into account with breaker close time setting
TCLOSD (set in cycles; see Figure 3.32). The Angle Difference Calculator
calculates the Angle Difference between voltages V
P
and V
S
, compensated
with the breaker close time:
Angle Difference = |(∠V
P
– ∠V
S
) + [(f
P
– f
S
) • TCLOSD •
(1 second/60 cycles) • (360°/slip cycle)]|
Angle Difference
Decreasing (V
S
* Approaching V
P
)
Angle Difference
Increasing (V
S
* Moving Away From V
P
)
Angle
Difference
Angle
Difference
Angle Compensation for
Breaker Close Time
TCLOSD
Angle Compensation
for Breaker Close Time
TCLOSD
Setting
25ANG1
(or 25ANG2)
Setting
25ANG1
(or 25ANG2)
Setting
25ANG1
(or 25ANG2)
V
P
V
S
V
S
*
V
S
*
V
P
V
S
Setting
25ANG1
(or 25ANG2)